Wall mounted luminaires or lights for illuminating outdoor areas are often equipped with a motion detector that switches on a lamp when movement is detected. The detector is commonly an infrared sensor that detects infrared emissions radiated by a body, but they may also be ultrasound sensors that emit a high frequency wave pulse and listen to the echo to detect any physical changes in the environment. In either case, the principle is to detect the presence of a person and automatically activate a light to illuminate an area so that the person can see their surroundings or so that others are made aware of their presence, if the light is being used for security purposes.
A common problem is that it is difficult to effectively position these lamps to light the required area, such as a pathway or courtyard, without shining light directly towards and into the eyes of a person when they are walking towards the light. Although the light can be positioned or orientated so that it does not shine directly into the eyes of an approaching person, it may then not effectively illuminate the required area.
It is known from EP 1,408,276 A2 to provide a system with a plurality of light sources and sensors that determine the position of a person. The light sources are controlled so as to generate maximum illumination at the person's location.
It is known from U.S.2010/0301767 A1 to provide an interactive lighting system for a clothing rack in which the lighting is controlled in dependence on the distance of a person from the rack.